


Poison From Your Sweet, Sweet Lips

by mattzerella_sticks



Category: Supernatural
Genre: Alternate Universe - Canon Divergence, Blood and Gore, Cannibalism, Case Fic, Caves, Confessions, Corpses, Cuddling & Snuggling, Dean Can't Cope, Demon Dean Winchester, Doppelganger, First Blade, Graphic Description, Leviathan Castiel, M/M, Mark of Cain, Mutilation, Non-Consensual Touching, Post-Season/Series 13, Psychological Torture, References to Addiction, Self-Harm, Tears, Torture, Unexpected Visitors, Walks In The Woods
Language: English
Status: Completed
Published: 2018-03-04
Updated: 2018-03-04
Packaged: 2019-03-26 18:37:54
Rating: Mature
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 8,070
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13863615
Author URL: https://archiveofourown.org/users/mattzerella_sticks/pseuds/mattzerella_sticks
Summary: After hunting for thirty-plus years, it takes a lot to really send Dean into a downward spiral. But a recent case stirs up some desires he thought he left far in the past, and leaves him feeling shaken. But just what did he see, what does he want, and how can he recover from the shock and horror of what waits in the night?(Set sometime after Jack and Mary get back from the Apocalypse World, where Michael and Lucifer were defeated, Gabriel runs Heaven, and Jack hunts with the Winchesters.)





	Poison From Your Sweet, Sweet Lips

**Author's Note:**

> Hello and welcome to my 50th piece of fanfiction on this site! I thought I'd challenge myself and I think I shot way past my expectations.
> 
> Now, this piece was originally going to be for a challenge, but when I went past the word limit I decided to just post as it. I'm not great at self-editing and I truly believe that everything here cannot be cut.
> 
> I hope y'all enjoy!

            He didn’t mean to break the skin. It just wouldn’t stop tingling, itching – _burning_. Dean wasn’t even sure how long he’d been scraping his nails up and down his arm, focusing on the sensation more than the words and images and _feelings_ from earlier in the day. Pushing those thoughts and memories down further and further so they don’t rise and spill over from his throat and out his mouth. Now, instead of staring at his wall he’s mesmerized by his bloodstained nails, and how he can’t stop picking, and the trail seeping down his arm, over his pale, unblemished flesh.

            ‘ _It’s not there_ ,’ he thinks, ‘ _It’s gone.’_

            ‘ ** _But you miss it don’t you?’_**

            He shivers, eyes fluttering closed as _his_ voice speaks up. It scrapes at the back of his mind, clawing its way back up. Sending shivers up his spine like the first hit after years of sobriety.

            ‘ ** _The power…_** ’ he continues, ‘ ** _The freedom…_** ’

            “Shut up,” Dean growls, digging deeper into his arm. The pain dulls the other’s voice somewhat, but it carries on like a bad song at a party. And no matter how far into the bathroom Dean tries to hide, how powerful the faucet water is, he can still hear it through the thin walls of his mind.

            He hadn’t thought about him in forever, but today’s events have proven that no matter how hard he tries to salt and burn the past, it’ll still be there to haunt him.

* * *

 

            “So what’s the story?”

            Dean leans against Baby, watching as Sam and Cas make their way over to him and Jack. The Nephilim distracts himself on his phone, only glancing up to smile at the two before continuing scrolling.

            Sam reaches them first. “Same as the witnesses,” he shrugs, “There’s no connection between any of the victims.”

            “What’s left of them anyway,” Cas says.

            Dean raises a brow, “…Left?”

            “We were able to see the victims’ bodies,” he explains, “Thankfully whoever did this didn’t take their identifications. Only because the police would never have been able to find out whose parts they found.”

            “Holy –” Dean huffs, stomach turning. It shouldn’t get to him, this many years into the job, but knowing what a half-there corpse means still makes his nerves fry and his knees knock together. “So,” he continues after a deep breath, “what are we thinking? Werewolves?”

            “There weren’t any hearts on the bodies,” Sam says, “But… the spread of the victims doesn’t match up with any lunar cycles.”

            “And we don’t have any reason to believe vampires either,” Cas adds, “At least two of the victims were reported missing early morning, and discovered before the sun had set.”

            “How does that rule out vampires?” Jack, phone away, blinks up at them. “I mean,” he continues, “Couldn’t they have had help? From my conversations with Alex, vampires were not above using humans as bait.”

            “Maybe,” Sam says, “But get this, when they swept the area for clues, one of the officers strayed from the pack.”

            “And?”

            “And they found her,” Cas pulls out the photo from his trench coat, handing it to Dean, “They didn’t hear a thing.” Dean forces himself to look at the grisly scene. The young woman, probably fresh from the academy, hangs from her own intestines. A once blue, pristine uniform was stained with her blood.

            “So,” Dean hands the picture back, “We’re looking for… what, exactly?” Sam and Cas share a look, one that doesn’t sit well with Dean.

            “We’re… not sure,” Sam starts, “Every new angle we get on this pulls us farther and farther away from anything we’re used to dealing with.”

            “So, what?” Dean asks, “We’re looking at something new here?”

            “I’m not sure…”

            Dean turns to Cas, now. The angel is looking at his feet, hands stuffed into his jacket. His face creases, and Dean watching the gears spinning as he tries to work through his thoughts.

            “What’re ya thinking, Cas?”

            “The bodies… I don’t know,” he says, words slow and unsteady, “When we were examining them, I sensed this – this energy. It was… familiar.”

            “So angels?” Dean asks, Jack and Sam leaning in with interest.

            “Not angels,” Cas shakes his head, “Demonic… with a little something _extra_.”

            “Demons would fit,” Sam says, “But there weren’t any signs – no weird weather patterns, cattle deaths. I even asked the sheriff if he smelt any sulfur! Not a thing.”

            “Still…”

            “Look,” Dean cuts in, clapping a hand on Cas’s shoulder, “We don’t have much to go on but that. I say, until we find anything else, we treat this as a demon hunt.” Cas smiles at him, causing his stomach to flip in an all-new way – a way he likes. He squeezes once more before dropping his hand back to his side.

            Sam waits a beat, but agrees with them. “So,” he says, “since we have an… idea of what we’re hunting, I think we should strike before anyone else gets hurt.”

            “Where would we begin?” Jack asks him, “All these people were taken in different parts of the city?”

            “But their remains were all found at the entrance of the woods,” Cas says, “They weren’t always consistent… but at least four of the victims were found near this stream on the East side.”

            “So we start there,” Dean says, “We should split up –“

            “Split up?” Sam splutters, “Are you serious?”

            “What?”

            “This… this thing –“

            “Probable demon.”

            “Demon, monster – whatever!” Sam barks, “It’s already got twenty-two bodies under its belt –“

            “Twenty-two?” Dean blinks, his throat suddenly dry, “We… why didn’t we get that in the report?”

            “A lot of them didn’t have enough left behind for identification,” Sam shrugged, sadly, “Police think the perp might have started in on homeless people or tourists – those that no one in the town might have noticed.”

            Dean wipes a hand down his face, sucking in a harsh breath between clenched teeth. “That’s just great,” he mutters, “Really freakin’ great… all those… all those people –“

            “It’s strong, whatever it is, Dean,” Sam continues, “we can’t be certain that splitting up won’t just make it easier for them to take us out.” Dean tries not to let his brother’s worry get to him, but he’s still focused on the number of people they were too late to save. He’s spiraling, but thankfully Cas clears his throat before he freefalls.

            “I’d agree with you, Sam,” Cas speaks up, drawing the brothers’ attention, “But I’m going to have to side with Dean on this one.”

            “Cas…”

            “Look at the time, Sam,” he says, “I think that by splitting up, we’d be able to cover more ground before the sun sets and by then numbers wouldn’t matter. The monster has better knowledge of the surroundings, so if we want to put an end to this now, we must act quickly.”

            Sam frowns, his cheeks dimpling in dissatisfaction. “Still…”

            “Jack and I will be in constant communication,” he adds, “That way, if Dean and I find anything, I can alert you and vice versa.” He looks at Dean, “Besides, I think we’ve handled enough crises together that as long as none of us face this threat alone, we’ll be alright.” Dean smirks the tiniest bit, looking at Sam. The look on his brother’s face is exasperated, but fond.

            “Alright,” Sam relents, “Jack? You good with this plan?”

            “I want to end this,” he says, “This seems like the best plan we have.”

            “Great!” Dean claps, drawing all eyes to him, “Let’s get moving, then. Cas, take shotgun – that way he doesn’t have to move when we drop you and Jack off, _Sam_.” The younger Winchester huffs something under his breath, rolling his eyes and stuffing his long frame into the backseat next to Jack.

            Cas opens the door, but pauses with one foot on the frame. Dean catches his eye, raising his brow in question. “Nothing,” Cas says, “Just… appreciating the power.”

            “Shotgun doesn’t hold much of a sway,” Dean scoffs, “I mean, you can’t pick the music.”

            “…Can’t I?”

            He quirks his own brow to match Dean’s – in challenge. Dean doesn’t want to be the first to turn. But the fierce intensity of Cas’s gaze is like coal under his feet, and he can’t handle the burn. He ducks his head in defeat, “…We’ll see.”

            Cas’s choices aren’t that bad.

* * *

 

            The sun is just starting to set over the horizon. Dean and Cas have been at this for hours, but after passing the same tree for the third time, he’s ready to call it quits. Pressing himself against the small carving, he whistles over to Cas, who has taken to the birds.

            “Yes, Dean?” he asks, trotting over the brush and thistles coating the ground, “Did you find anything?”

            “Only a pinecone in my boot,” Dean grumbles, “I think we’re barking up the wrong tree – pun intended. Whatever was lurking in these woods must only come out at night.”

            “I’m not sure,” Cas tells him, turning, “The energy here is… off. The animals feel it, and it has been throwing certain balances into upheaval.” Birdsong catches their ears, and Dean tries to quell the soft coo working its way up his throat at the sight of Cas, nodding along in conversation.

            He pushes himself off the tree, wiping his hands. “So,” he says, “Did the birds see where the monster went or what it looks like? You gonna make ‘em sing like a canary?”

            Cas looks at him, squinting and tilting his head. “…It’s not a canary, Dean,” he says, seriously, “It’s a blue jay.”

            Dean nearly snorts a chuckle, but someone beats him to it. Its raucous laugh rings out, bouncing against the trees, and startles the birds from their perch. The sound is followed with harsh ruffling and heavy steps.

            Dean meets Cas’s wide eyes, “ _Shit_.” They give chase, Dean taking lead, knocking away heavy branches and jumping over fallen logs, Cas trailing behind. Dean can barely make out the creature, its shadowy figure darting just out of sight – always a few steps ahead of them.

            He’s rounding the bend when he hears it – the crack of wood caving in on itself. Dean looks to his left where a large oak hurdles towards him. He’s frozen, gaping up as the trunk comes closer and closer until –

            “Dean!”

            He’s pushed away, tumbling with the weight of someone else down a steep hill. They roll until they reach the bottom, curving into a barren field. Dean opens his eyes, ready to fight, only to be face to face with Cas. His blue eyes are flitting all across Dean’s face. He’s pinned him there, squeezing his wrists too tight to be comfortable or fun.

            “Are you okay?” Cas asks him.

            Dean sighs, “Yeah… yeah, you got me out of there at the last second.” He pushes up, forcing Cas to kneel between his legs. He scratches at his neck and looks back up at the hill, where the jagged remains of the tree sit ominously. “That was real close,” Dean says.

            “Too close,” Cas says, “I should let Jack and Sam know where we are.“

            “Why bother?” Dean huffs, standing. He holds a hand to Cas, pulling the angel up alongside him. “I mean,” he continues, “Not like we know where he went.”

            “He?”

            “I’m pretty sure,” Dean shrugs, “Height, build… didn’t get a good look at the face but that voice? It’s a dude.”

            “Very well,” Cas powers on, “Still, we should check in. It’s going to be dark soon, and I don’t believe we’ll be out of the woods when the sun sets. If we meet up, we will have more eyes.”

            Dean doesn’t want Sam to make his way over. He didn’t tell Cas, wasn’t sure how to bring it up, but he recognized the laugh. It cut clear through his heart, scraping like nails on chalk in his mind. Made his heart stop and throat close. The only problem is he couldn’t match the sound to a face or a name. His body had such a striking physical reaction, but for the love of him he couldn’t connect the dots. The string is hanging in the wind, dangling precariously over the dark chasm of his memories, reaching out. But either he can’t remember… or he doesn’t want to.

            And if it’s the latter, then it’s for a good reason – one that warrants Sam being _far_ away from here.

            _Snap_.

            They turn to their right, where the sound came from. Dean pulls out his gun, finger perched on the trigger. From the gleam of silver Dean catches at the corner of his eye, he can tell Cas is ready with his blade. They take a tentative step forward, only to jump back when something flies out.

            Dean fires first, the gunshot echoing and scaring off even more animals.

            It didn’t even matter – all Dean did was waste a round. Lying at their feet was a dead bird – a _blue jay_. Probably not the one from earlier, but he couldn’t tell. Cas would know.

            _Snap._

            “He’s playing with us,” Cas says, kneeling towards the creature. He scoops it into his hands and glares at it. After a few seconds, his concentrated frown deepens into annoyance.

            “Cas?”

            “My powers,” he whispers, going wide-eyed, “I can’t… I can’t heal him.” Dean looks towards the bush, where the monster snaps another twig, more impatient than before.

            “We’ll be walking into a trap, won’t we?”

            “Most likely,” Cas says, leaning back down to let the dead bird slip softly from his hands. He covers it with fallen leaves and offers a few words in Enochian. He stands at full height, the softness in his eyes shedding into a hard fury. “Whatever we’re facing… he’s powerful. And…”

            “And?”

            “Familiar,” Cas says, again, frustrated, “I can’t help but feel we’ve faced something like this before. It’s like hearing a song… but the melody is off, and the words are not quite the same… I’m sorry if I sound –“

            “No, no,” Dean assures him, “I… I get it. I feel the same way… sort of.” Cas tilts his head, as if to ask how, when another animal is thrown from the brush: a tawny rabbit, neck broken. Its lifeless eyes stare up at them, and cut their conversation short.

            “We shouldn’t keep him waiting,” Cas says instead, walking forward. He looks back at Dean, “Coming?”

            “Right behind you.”

            Dean brings up the rear – alert to whatever might come at them from the side. The angel doesn’t look anywhere but ahead. They follow a marked path, the monster slicing and slashing into tree bark, giving the wood an eerie smile. Dean brushes a few fingers against one and bites back a gasp, the electric shock firing up his hand and leaving fresh tingles in its wake.

            He keeps his hands to himself after that.

            Cas and Dean stop soon enough in another clearing. There’s no sign of life – creature, animal, or plant. The grass is dry and grey, crumbling underfoot wherever they step. There’re carcasses and bones littered everywhere, and Dean gags when he recognizes what looks like a femur. It’s too much, the smell of rotting flesh hitting his nose and sending his brain into overdrive. He searches for Cas, gripping his free hand.

            “Any,” he struggles, voice wavering, “Any word from Jack?”

            “I sent out a prayer,” Cas says, “It’s up to them to find us in time.”

            _Snap!_

            There’s a large cave a few yards away. Its smooth rock entrance is painted in blood, and the bones planted at its ground only serve to make the mouth look more terrifying.

            That’s where the sound came from.

            “I’ll take ‘Creepy Murder Hideouts’ for $2000, Alex,” Dean mumbles. Cas’s stare assures Dean his humor is not appreciated. He squeezes Cas’s hand in apology before letting it drop, re-centering himself, and tuning the horror around them out.

            “Well,” Dean says after a while, “It’ll be rude to keep him waiting.” He steps forward, leading the charge. Cas stays a few inches behind, trench coat fanned around him like a cape.

            _Snap_

_Snap_

_Snap!_

            Dean passes the ‘teeth’, stepping into the cave. There are a few tentative steps of darkness, but not for long. He pulls a flashlight from his pocket and flicks it on, letting them catch glimpse of the monster’s home.

            He wishes he didn’t.

            Where the blood around the cave was painted in chaos, its only purpose to serve as warning for anyone who came across it that they’ve found their doom. Inside, each stroke was made with intent. There are symbols and sigils streaked within, the dark red of dried blood shining whenever a beam of light catches it.

            Dean moves forward and away from Cas, pocketing his weapon to trace at one of the symbols.

            “You said there weren’t any angels involved, Cas,” Dean whispers, “Then how come there’re all these?”

            “I… I do not know,” Cas admits, voice warbling “It’s… These are… I…” Dean turns to him, watches as his eyes ping pong across the cave walls, taking it all in. “These symbols… I recognize a few… but not… haven’t seen –“

            “Cas?”

            “Don’t you feel them, Dean?” Cas turns to him, eyes glassy and distant, “Like black tendrils, gripping at you, trying to tear you apart? So many voices… like before but not… I don’t… I can’t…” He trails off, looking to his right, towards something Dean can’t see.

            “Cas…?” Dean reaches out, eyebrows drawn close together in worry, “Talk to me. Tell me you’re – oof!”

            Cas spins on his heel, knocking Dean back as he scurries deeper into the cave. “Cas!” Dean shouts, “Cas!” He chases after him, uncaring of who hears or not. It doesn’t matter to him what’s waiting inside knowing that Cas is vulnerable.

            He follows the heavy pounding of Cas’s footsteps, turning and twisting down the surprising length of the cave’s tunnel systems. Throughout it all he could barely see six inches in front of him. But the light at the end has him picking up his pace, uncaring to the way his lungs were burning.

            He slides into an opening, sagging against his knees in exhaustion, trying to catch his breath. When he feels he has a hold on it, he looks up – and loses it once more.

            The flashlight is pointless, as the room is engulfed in the bright light of the tear in the fabric of the universe. It glows and pulsates with that strange energy, larger than any rip Dean has seen before.

            And standing right in front of it is Cas, his back to Dean. He’s gazing up at it with hands in his pockets, his posture more loose and relaxed than before, frighteningly so.

            Dean is on high alert, taking careful steps towards his angel. “Cas?” he says, “Buddy, is that… we should probably step away. Wait until Jack –“ He loses his voice, unable to speak past the sheer terror and wrongness he feels when Cas turns around.

            It’s not him. It’s not _his_ Cas. This Cas’s collar is flecked with blood, his hair is mussed and his eyes dark, and everywhere across his skin are black tendrils, goo flowing where blood should be. He’s grinning at him with sharpened teeth, predatorily, ready to snap.

            “Lev…” Dean croaks out, “Leviathan.”

            “Hello, Dean,” he says, then glances at something slightly to the left, “And hello, Dean.”

            “What –“

            Darkness. He slumps to the ground.

* * *

 

            “ – try and wake ‘em up… I’m bored!”

            “Patience, love, why must I keep reminding you of this?”

            “Because I’m a _naughty_ piece of shit who loves your ‘ _reminders_ ’.”

            Dean wakes with a silent groan, trying and failing to stretch his aching limbs. His arms are pulled tight behind him, around a jagged rock that pokes deeper the more he wriggles. His legs were left free, fanned out beneath him in an open ‘V’. There’s a weight pressed up against him, and he blinks to adjust to the tear’s light to see Cas, still knocked out. Dean shakes his shoulder, trying to jerk him awake. There’s a slight twitch behind Cas’s eyes, and Dean keeps going. “Cas,” he whispers, “Cas, come on. Cas –!”

            Rough, calloused hands grab his chin and pull his gaze forward, locking eyes with a recognizable pair of green eyes.

            “Well look here, baby,” the other Dean says, face dirty with sweat and blood, his grin feral, “I guess we can start playin’ after all.”

            Dean shudders involuntarily, backing himself further into the rock behind him. “What?” he asks, “Who are… what?”

            The other Dean lets go, leaning back in a fit of laughter, his arm clutching at his stomach. “Oh man, did I hit you too hard?” he wheezes, wiping an errant tear from his eye, “Don’t you recognize me… or, well – should I say you?”

            “Now don’t patronize him love,” Leviathan Cas growls as he stalks forward, wrapping his arm around Dean’s stomach, tangling their fingers together. Pressing up against other Dean’s back, he hooks his chin over Dean’s shoulder and scrapes his stubble against his. “This must be confusing,” he continues, “It’s not everyday you run into other versions of yourself.”

            Dean wants to make a comment: about how this isn’t the first doppelganger he’s come across, that even if it was he’s a big boy, or maybe even about the tender press of his twin’s lips against the bundle of creatures’ flesh suit. He wants to, but all his confidence and bravado shrivels when _his_ Cas finally stirs awake.

            “…Dean?”

            “The gangs all here!” Dean crows, stepping out of the Leviathan’s hold, “Now we can _really_ get this party started.”

            Cas’s eyes widen at the sight, turning to Dean. He doesn’t know what he can tell the angel, his mind still coming to terms with what he’s seeing.

            “Now come on, keep your eyes on me,” other Dean whines, “I take it personally if I feel ignored.”

            “So, what?” Dean finally finds his voice, “In your universe you’re a big baby? Not impressed, honestly.” Other Dean smirks at him.

            “You shouldn’t be impressed,” he says, eyes flicking black, “You should be _scared_.”

            And he is. The cloying, sick feeling has returned, choking him with the sheer sense of _wrong_. There’re no bodies littered about the cave floor, but Demon him reeks of rotted flesh and organs, his clothes as dirty as his face. A sneaking suspicion has him trekking his eyes away from his face and down his right arm, where the veins are red and bulging around scar tissue, and he’s swinging a jawbone blade in hand.

            “This doesn’t make any sense,” Cas says, “You weren’t… at no point should either of you have existed at the same time.”

            “Call it fate… destiny – I don’t care,” Demon Dean shrugs, “Where we come from, we played our cards exactly how we should have.”

            “And it was all happily ever after wasn’t it?” Dean chokes out, “All sunshine and rainbows?”

            “Those don’t exist where we come from,” Leviathan Cas tilts his head, cutting at Dean’s heart, “Not anymore. Our universe is… _pure_. No mess, no fuss, just survival – people stripped to their most base instincts and desires.”

            “So Purgatory,” Dean says, “you turned your universe into Purgatory?”

            “You’d be surprised how great it is when there’s nothing holding you back, Dean,” Demon him adds, rubbing his hand up and down Leviathan Cas’s cheek, “You get to do all the _fun_ things Daddy tried to beat out of you.” Dean flinches, the words striking below the belt, just as they intended.

            “But the Leviathan,” Cas struggles to understand, “my vess… my body could not handle the strain it… it nearly killed me.”

            “Only because you _let_ it,” Cas’s doppelganger points out, “The Leviathan are repelled by willpower. The stronger you’re beliefs, the harder it is for them to take control. I wasn’t swayed from my convictions… I managed to tame and absorb these creatures. They work for me – are a _part_ of me. I reveled in their power. I stared into the abyss and _didn’t blink_.” Cas is forced into a stunned silence, eyes trained on his shoes, unable to meet the other Cas’s smug look.

            “And you?” Dean asks the other him, “Obviously why I got the Mark here won’t match with how you got the Mark there so…?”

            “With Cas all souped up on Leviathan juice, we needed something that could take him down,” Demon him shrugs, picking at his nails with the First Blade, “Crowley wasn’t feeling too good about being cut out on all that power, so he decided to ‘help’. Sam and I decided, what the hell, not like we have any aces up our sleeves. This one,” he jerks his thumb back at the Leviathan, the other Cas smirking softly, “wouldn’t listen to ‘ _reason_ ’. So with Sam setting up base in Crowley’s, we went on a little trip to a bee farm.”

            “Cain wouldn’t budge, no matter how Crowley spun the situation,” he said, “So I challenged him to it. Winner keeps the Mark… loser gets – I think you can guess. It was exactly what we needed on our side. Who needs an army when you have a super-powered demon on your side am I right?”

            “It doesn’t look like you were fighting for long though,” Dean says, “How did you… you and he…”

            “Hook up?” Demon Dean chuckles, winking exaggeratedly at him, “After a while, I was starting to get pissed with Sammy. He was going on and on about the ‘dangerous effects of the Mark’ and ‘you’re losing your humanity, Dean’ blah blah blah blah _blah_. I was getting sick of it. So… during one battle, Cas managed to catch me alone. Put a deal on the table for me – offered me something I’ve been _craving_ for a long time now.” He twines his free hand with the other Cas’s, grinning, “I’m sure you can guess what that was.”

            “I take it your Sam wasn’t happy with the team up?”

            “If he was, he didn’t put up a fight,” Demon him tosses out, “but when you’re stabbed through the back you don’t have much time to do those types of things.” Dean’s breath hitches at the cold way the Demon version of himself talked about his brother. Like he was just another of a long list of bodies he let hit the floor.

            “After that, there wasn’t really anything standing in our way of taking control,” Demon Dean carries on, “What with Cas sitting pretty on his perch up in Heaven as the new God and me overthrowing Crowley… we had everything we ever wanted.”

            “So why leave?” Cas demands, glaring at Dean’s evil copy, “Why step through the portal.”

            “Honestly we didn’t know we’d end up here when we touched it,” Demon him says, “Things like this don’t pop up everyday, especially in our bedroom.” Dean can see Cas flinch out of the corner of his eye, “And I don’t take kindly to things interrupting our special alone time, just when I was about to –“

            “Anyway,” Leviathan Cas speaks over him, “After… cleaning up, we investigated and landed here –“

            “Got a good look around, took some pictures, held up the Hollywood sign,” Dean rattles off, snarling, “So end your vacation and get out of here.”

            “I don’t think so,” Leviathan Cas says, walking towards him. He holds Dean’s cheek, grazing his thumb under his eye. Dean can feel his Cas’s glare even if he can’t see it. “Do you know how _boring_ it is to have everything you want? When all challenges you’ve faced have been conquered?”

            “Sounds like paradise.”

            “Well it wasn’t,” Demon him says from behind the Leviathan Cas, arms folded across his chest in a huff, “We were just going through the motions for the longest of times. Every morning we’d walk throughout our world reminding our subjects who to fear; there’d be the occasional reminder being dragged forward once or twice to feel the smooth slide of my blade. Then we’d carry on to the afternoon where we would attend the daily gladiatorial battles, watching as humans, angels, demons, and monsters fought for their glory. And later in the evening they’d receive it – a five-minute head start before I hunted them down and skinned them for our collection. It was getting too… _easy_.”

            “So your little stay in our universe is just so you two can get your _groove_ back?” Dean splutters, “Are you guys for real?”

            “They do say nothing spices up a relationship like returning to your roots,” Demon him says, “I think conquering your world will put us back on track to where we were before.”

            “Dean is right,” Leviathan Cas stands, turning to embrace his lover with a fire burning behind his eyes, “Our first night here was… _glorious_. We had stumbled upon a vagrant during our scouting, and I watched as Dean had pounced on him, slowly torturing the life from him. He flayed strips of skin from his body… pounded bone into dust… used his intestines to keep him from wriggling away as Dean pulled nail after nail, slicing one finger after the other. It was _titillating_. Making something spark inside me that hasn’t been lit in years. Soon hours had passed, Dean working his magic. I couldn’t control myself any longer and joined in the chaos. As I was reaching climax, I watched from behind Dean as the man’s eyes glazed over with death, his last sensation that of Dean spurting over his wounds as I came in Dean.” He pulls a string of teeth from his coat pocket, holding them up in the tear’s glow, “He made me a keepsake so we could remember the fun we had.”

            “Not like we could keep the skin,” Demon him had shrugged, “I fried that up for breakfast after we cuddled over the bloody corpse.” He winks at Dean, “Goes great with scrambled kidneys and hash _brains_.”

            Cas chokes beside him, dry heaving the bile that sits in his stomach, trying to keep it down. Dean can’t even begin to pick apart the story he heard. Each part a cacophony of terror and disgust that are fighting for dominance over which part this reflection of him, this _thing_ that used to be him in another world, did that was the worst. The answer though was simple – Demon Dean himself was the worst part. Because he had done it, had found nothing wrong with doing it, and would do it again.

            “And the others?” Dean forced himself to ask, to focus on anything but the manic glee and arousal on full display, “They played a part in your weird sex games?”

            “A man’s gotta eat, Dean,” Demon Dean snarks, tapping at his stomach, “And chasing people through the woods really works up the appetite.”

            “And you?” Cas asks his copy, regaining control of himself, “Did you… hunt?”

            “It’d be no fun if I participated,” Leviathan Cas shrugs, “They’d be nothing but bones with the snap of my fingers. Besides… my interests are _voyeuristic_ in nature.”

            “A regular ol’ Peeping Tom,” Demon Dean jokes, “But you gotta love him – flaws and all.”

            “From what I’m seein’ you two are nothin’ _but_ flaws – _hrrgn_.”

            Demon him has pressed the First Blade right against his neck, and the teeth are tugging against his skin. Green eyes have blinked back to black, and Demon Dean’s leaning in close. “Wanna say that again, pretty boy?” he threatens, “I’m not a fan of people who make fun of what’s _mine_.”

            Dean tries another comment, but the pressure chokes and strangles any word that tries to escape.

            “Down, love,” Leviathan Cas places a hand on his Dean’s shoulder – _the_ shoulder, “Don’t take it out on them. They’re just misguided and… well, _weak_.”

            Cas speaks for the both of them as Dean splutters for breath, “…Excuse me?”

            “From what we can tell, it seems you two have had ultimate power at the tips of your fingers,” Leviathan Cas explains, “And _wasted_ it. Letting it go because of some misplaced sense of morality. Always doing what you expect is right,” his gaze flitters between the two, “Not because of what you _want_.”

            “Put it simply you two are nothin’ but wet blankets,” Demon Dean mocks, “Probably spend your days twiddlin’ your thumbs and holding back. Because if you’re happy than somethin’ must be wrong, am I right? I mean, Heaven forbid you feel good about yourselves.” He points between him and his lover, “We feel good. _This_ is good.”

            “What you two share is nothing more than an addiction,” Cas hits back, his words biting into Dean’s heart, “You push each other deeper and darker into depravity, feeding off your worst impulses. No wonder there’s nothing left in your world – you two are _toxic_.”

            “But isn’t that just love, angel?” Demon Dean asks, gripping Cas’s hair and pulling him close, “I can take the poison as long as it comes from your sweet, sweet _lips_.” He springs forward, shoving his tongue down Cas’s mouth, battling him into submission. Cas’s legs kick out underneath, eyes open and _glaring_ with such power Dean cowers at the sight.

            Demon him lets go, wiping at his spit-slick lips. “Feisty,” he says, “But not as good as the original.”

            “He _is_ the original, you sick monster –“

            “Now Dean,” Leviathan Cas cuts him off, “Is that any way to talk about yourself?”

            “He’s probably jealous,” Demon him purrs, leaning against the other Cas’s shoulder, “Thinks I’ve probably tainted his widdle angel –“

            “Shut up!”

            “Why don’t you make me?” the other him says, plopping onto Dean’s lap with a giddy laugh. He grinds against Dean’s groin, and Dean wants to vomit feeling how hard the demon is. “It’d be fun,” Demon him taunts, “Didn’t you ever wonder? Oh I know… you _have_. No one knows your body like yourself, and I can show you a few _places_ you might not have even thought about.” He leans in to whisper at Dean’s ear, “Normally I’d be on the other end, but I’m feeling _charitable_.” Then he slides his tongue across Dean’s cheek and dives into his mouth.

            Dean can’t move. Demon Dean takes his pliant body underhand and keeps moving up against him, rutting and touching. Blood flecks fly off him and onto Dean, staining his clothes, imprinting him with the stench of his copy. It’s dirty, disgusting, and immoral… but the worst feeling – the one that is niggling at the base of his brain – is that it feels _right_.

            Through the press of their mouths Dean can feel the Mark singing to him, filling all the cracks in his soul with the promise of being complete. He thought he would never have to hear Amara’s voice again, but that universe’s Darkness is still trapped in the Mark, and knows exactly which buttons to press to mess with Dean’s head. Make him crave the release he thought he didn’t need. He’s flexing his hands against his binds, searching for something he can’t name.

            “Like that?” Demon Dean asks, nibbling at his lips, trailing kisses down his neck. Dean can’t focus, his mind dizzy in a haze. “You know,” the other him continues, “if you want… I can share it with you. I can see it in your eyes… you miss it. Miss this _feeling_. Like strings being cut – getting the power to do what you want when you want it. It’s _intoxicating_ … such a rush –“

            “Dean, no!” His Cas says, cutting through the fog the Mark emits, “Fight it! You’ve been able to resist it before, you can do it again!”

            “You say that now,” Leviathan Cas snickers, leaning towards Cas, “But are either of you really strong enough?” He clutches at Cas’s trench coat, dragging him forward, “He’s not the only one who can have a second chance, you know? I can teach you how to tame them, give you the ultimate power. Make you _useful_ again.” The Other Cas’s hand starts glowing with a dark energy, and the power leaks out.

            Cas’s eyes go wide, and he tries to lean away. He’s muttering in Enochian, pressing himself against Dean.

            Demon Dean has his own hand held up, the Mark glowing an even brighter red than before. “What do you say, Dean?” he asks, “Want to be the best you that you can be?”

            They’re inching closer and closer, ready to mold them into the same warped versions from their world. Dean doesn’t see a way out, so he focuses all he can on the warm weight of Cas next to him – hopefully they can resist long enough they would die before they turned.

            He doesn’t want this. Doesn’t want this Cas.

            He never wanted them to happen like _this_.

            Demon Dean’s hand is hovering over his wrist, the intense heat he gives off scalding. His fingers are about to touch his skin and –

            _Boom!_

* * *

 

            They didn’t have the radio on the entire drive back. Sam tried to find something, but a rough ‘Turn it off, Sammy’ from him kept all hands and minds away from music. Dean didn’t look away from the window the entire time, his hand cradling his right arm.

            He got out of there unscathed, as did Cas.

            Jack and Sam had found them with little time to spare. The nephilim had reacted without thought, extending his powers to push the doppelgangers off of them and towards the cave walls. Sam rushed to check on Dean and Cas, but faltered when he noticed just whom they were facing.

            “Shifters?” Sam had asked. Dean shook his head and pointed weakly to the rift.

            It was two versus two; Dean and Cas too weak from shock to even stand properly. Demon him had taunted Sam, talking about his own brother and how they had handled his corpse: propped above their marital bed, eyes sewn open. Leviathan Cas tried to strike after that – but Jack was more powerful.

            He didn’t kill them – he couldn’t kill them. Their deaths would release only another can of worms they couldn’t face again.

            But Jack could weaken them. He started with one – pulling a small tendril of goo from under the other Cas’s skin and grinding it into nothing. Then another, repeating the process the longer they stayed in the wrong universe.

            It hurt to see the tender way Demon him had cradled his Cas, carrying him over towards the rift. Demon Dean had looked back, speaking directly to him. “We’ll find a way back,” he promised, “If we’re two things, it’s immortal and _stubborn_. Nothing can stop us.”

            He vanished, as well as the rift moments later.

            Jack caused a cave-in just to be sure.

            When they get back to the Bunker at daybreak, having driven all throughout the night, Dean doesn’t wait for Sam to take the keys out before he’s running off to his room, head ducked down in shame.

            “Dean, your arm!”

            He looks up towards Cas, the angel watching him from the open door. ‘ _Didn’t I lock it?_ ’ He wasn’t sure how much Cas had seen, or how long he’d been there, and all he can do is make a soft, low pitying sound from deep in his chest.

            Cas gives him a fond look, and steps in. He reaches out to Dean, “Please, allow me –“

            “No!” Dean flinches, hating himself even more as Cas’s face drops into something sadder. “N-no…” he says again, quieter, “I… I need it.”

            Cas sits at the edge of Dean’s bed, giving him distance. “What do you need it for?”

            “It helps,” Dean says, breathing harshly through his nose, “Keeps m’focused. _Grounded_. From thinking about… wanting…”

            “They’re gone, Dean,” Cas says, “There’s no chance of them coming back.”

            “How do you know?” he hisses, “How can you be _sure_?”

            “I…” Cas looks away, clenching and unclenching his fingers in thought. Dean thinks he sees dark swirls spinning out from them, but blinks away the illusion.

            “I can’t,” he finally says, turning to Dean, “But I won’t let their threats hang over me. And neither should you.”

            Dean wants to believe, having spent the entire ride back arguing with himself about what’s next. The bloodstains on his sheets clearly show who won there. When Chuck and Amara disappeared, he thought they had taken any lingering influences the Mark might have had on him.

            He was a fool to hope. The curse still held power over him, whether it was from his universe or any else’s. There could be thousands of places where he still has the Mark, and any one of them could break through next and offer Dean the same thing the other version of him had promised.

            And he doesn’t think he’d be able to fight it.

            “I’m just like they said,” Dean says aloud, “Weak…”

            “What?”

            “I’m weak,” Dean repeats, eyes brimming with unshed tears, “I was gonna say yes – _again_. I forgot how… forgot how _good_ it felt with it – the power. I knew what would happen, knew _who_ was waiting behind the scar, but I still… I still felt I was gonna say yes. Even if it would turn me into _him_ ,” A tear slips past, “I’m _weak_.” His chest is wracked with a loud sob, and he moves to bury his chin in his chest. He hiccups, trying to reign himself in – but once the floodgates were breached there was no stopping him.

            “Dean,” Cas says, grabbing for his hand, “Dean look at me.” He shakes his head, but Cas just puts a finger under his chin and pulls him forward. He’s looking right into Dean’s eyes, shining with a fierce conviction that makes him shudder. “You are one of the strongest people I know. You would have fought the Mark – would have been _nothing_ like him.”

            “You don’t –“

            “Today was nothing more then a bad day,” Cas assures him, “You didn’t expect to face them, didn’t think that you’d ever be offered the Mark again. I could feel your determination to resist near the end, using it to strengthen my own fortitude. You weren’t going to say yes… you were going to _fight_ , even if it was for naught.” He uses his other hand to run his fingers through Dean’s hair, giving him something to focus on other than the pain. Dean’s sobs start to weaken, breaths coming out nicer and more even.

            “They weren’t right,” Cas whispers, “They aren’t strong… we are. We knew that all that power was wrong, and we fought against it. I tried to send the Leviathan back, worked with you even when all I wanted to do was stay in the safety of my insanity. And whereas I took that power to further some selfish, ill-conceived plot, you only bore the mantle of Cain to save the world. You struggled to keep your humanity, and saved the world not through violence but through _love_. Your ability to care has stopped countless battles, saved millions of people. You’re stronger than that other Dean. You’re… you’re stronger than _me_.”

            Dean shakes his head. “N-nuh-uh Cas,” he says, “You’re the strong one. I don’t… I don’t know how many times you’ve been knocked on your ass, but you just keep going. You power through all the drama and fight to protect us even though there’s no reason for you to. You could have checked out at any time – after Lucifer was caged, after Purgatory, Metatron, Amara, every day you can just walk away and live your life but you don’t. You stay and you work to help people because _you_ care. Even now, you faced the same crap I did and you’re here comforting _me_! If I had gone through even half the stuff you’ve been through… I don’t know if I’d be able to…”

            Cas smiles, sliding his hand down from Dean’s hair to his cheek reverently. “To me all of that is but a blink in my existence, Dean. You’ve faced a lifetime of hardships, yet are still as bright and pure as the day you were born. _That_ takes strength.”

            The finality in Cas’s voice erodes any other argument Dean might have. He just lets Cas pad his thumb over his cheek, wiping away any traces of their cracked reflections.

            “Some days,” Dean says, finding his voice, “It hurts holding back. To not go for what I want. It… it sucks not giving in. Things I want that I… I don’t think I can have.”

            Cas tilts his head, “What makes you think you can’t have them?”

            “S’like what they said,” Dean admits, “If I have them… then I’m happy. I don’t get to be happy.”

            Cas smiles at him, sadly. “You, more than anyone, deserve happiness, Dean.”

            “And you?”

            He freezes, startled by the question. “Um,” he blushes, looking away, “What about me?”

            “Don’t you deserve happiness?”

            “I am,” Cas tries, forcing the words out, “I am content as I am now.” He doesn’t dare meet Dean’s eyes, pulling his hands away towards his lap, leaving Dean with cold skin and an empty heart.

            “Well I’m not,” Dean whispers. Cas whips towards him, eyes wide. Dean presses further, “I want _more_. This… this… whatever we are isn’t enough for me. I don’t want a day to pass where you don’t know you’re special and kind and _needed_ but I can’t… I can’t get the words out right, no matter how I try. But if you’re happy where you are then I… I should learn to be, too. Because my happiness kinda hinges on your-mmph!”

            Cas surged forward, capturing Dean’s lips with his. He squeezes Dean’s cheeks, scratching blunt crescent-shapes into his skin. Dean has barely any time to react, for as soon as Cas was on him, he’s pulling away, focused on a spot beside Dean’s head.

            “I’m… sorry, if that was a bit forward,” Cas says, voice raw with thick emotion, “But I… there were no words I could think of that could… could communicate the sheer joy I felt when you said those words.”

            A huge grin breaks out on Dean’s face. Now he’s reaching out, taking Cas’s chin in his hand. “I don’t mind,” he says, “I’ll never mind. We’ve wasted too much time not doing that.”

            “I agree,” Cas says. He looks down at Dean’s arm, gingerly prodding the area around his wound. “Do you mind if I…?”

            “Yeah,” he says, “But could you… do you mind if you…?”

            “Yes?”

            “Stay, after,” Dean looks away, feeling as his cheeks start to flush. “I feel better, but there’s still… I still –“

            “You don’t have to explain, Dean,” Cas tells him, “I’ll stay.” Dean’s grin softens around the edges, and he presses a dry kiss to Cas’s cheek as he mends the skin on Dean’s arm.

            They don’t take anything off – Dean already knowing he’ll have to wash his sheets in the morning, the dirt from their captivity already staining the clean linen. Cas presses himself on the pillows, and Dean to Cas. He’s twined his arms around Cas’s waist, and looks up through his lashes.

            “You think you could…”

            “I won’t let go,” Cas promises, his embrace tight and warm and _right_.

            Dean wiggles closer, pressing his face into Cas’s chest, trying to burrow in. Their legs are tangled, and the trench coat is surprisingly soft where it rubs against Dean’s skin. It’s childish and silly, he knows, to try and use Cas as a security blanket. But after today, nothing sounds better then curling up with his angel as Cas’s warm body chases away all the nasty thoughts just waiting for Dean to let his guard down.

            “We’ll never be like them, right?” Dean has to ask, waiting for the answer that’ll either pull him back from the precipice of sleep or push him deeper into unconsciousness.

            Cas gives it to him. “Never.”

            Coming from Cas’s lips, Dean almost believes it. But their lives are lived one day at a time – never knowing what will happen next. Dean might go on his last hunt, Cas could use up his final life, or even their universe could suffer from one last tear, collapsing in on itself. Their past and the actions that led them to where they are never truly fade away. They’re etched under the skin, leaving their marks and surging to life every now and then.

            But being in Cas’s arms, Dean feels that facing those ghosts won’t be as hard next time.

**Author's Note:**

> Ya like? Honestly with all those dimensions something like this could exist, and really if it was feasibly possible and could be done (without looking cheesy) the writers should think about it. At least it would serve as a good 'Greatest Hits' that the boys go out after fighting all the baddies they thought they beat earlier in their lives.
> 
> Drop a kudos or a comment to make me feel like my hard work was worth it!


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